Ottawa Public Health is warning that a horse was infected by another mosquito-born illness in the nation’s capital.
The risk that eastern equine encephalitis virus (EEEV) will be transmitted to humans is very rare, the public health agency said, but it has happened before.
EEEV is normally transmitted between wild birds and mosquitoes but can sometimes infect horses through bites, similar to other mosquito-born illnesses. Humans do not become infected from a horse or another human.
This comes just as OPH is reporting its second human case of West Nile virus (WNV) for the year on Aug. 19 in Ottawa.
WNV is found commonly in urbanized areas, whereas EEEV is found usually close to swampy or hardwood forests. Horses can be protected by a vaccine but there is no vaccines for people.
“Historically there have been three human cases of EEEV in Ontario, the most recent reported in 2022,” the health agency wrote in a press release. “There have been none in Ottawa to date.”
Both mosquito viruses are a concern, but EEEV can cause a “serious” neurological disease and even death, OPH said.
“Anyone who lives, works, or participates in outdoor activities in or around wooded swampy areas where the virus is active can be at risk,” it explained.
WNV continues to be a risk for residents in Ottawa, with the health agency saying to date it has trapped and tested 14 confirmed positive mosquito pools for the virus.
This according to OPH is “a notable increase over recent years.”
Here’s how to prevent mosquito-born viruses
The public health agency recommends that people use mosquito repellent containing DEET or icaridin and apply it to skin and clothing. DEET should not be used on synthetic fabrics, it notes.
Between dusk and dawn is with the insects are most active and near bushy or wooded areas. People are being reminded to protect themselves in those circumstances.
Light-coloured, tightly woven and looser fitting clothing should be worn. Long pants, long-sleeved shirt and socks and shoes can protect exposed skin.
Inside homes, people should be closing windows or have screens in good condition, the press release notes.
Standing water should be emptied around the home at least once a week because mosquitoes breed in it. Bird baths, outdoor toys, flower-pot saucers, swimming pool covers, old tires, wheelbarrows and buckets can all be areas where the insect can reproduce.
If there is a rain barrel on the property it should be covered with screen mesh at all times, the health agency said.